The present invention relates to an indication position calculation system, an indicator for an indication position calculation system, a game system, and an indication position calculation method.
An indication position calculation system has been known which calculates an indication position of an indicator on an indication plane (e.g., monitor or screen), such as a shooting game system using a gun-type controller or a presentation system using a pointing device. In such an indication position calculation system, an infrared light-emitting section or the like is disposed near the indication plane. The light-emitting section is imaged using an image sensor (light-receiving sensor) provided on the end of the indicator, and the indication position of the indicator is calculated based on the position of the light-emitting section in the resulting image.
In such an indication position calculation system, when the light-reception information relating to a pixel of the image is larger than a predetermined threshold value, this pixel is determined to be a pixel corresponding to the light-emitting section. The indication position of the indicator is calculated based on the position of such a pixel. Japanese Patent No. 2961097 discloses such technology, for example.
However, since a related-art indication position calculation system performs position calculations evenly based on pixels of which the light-reception information has been determined to be larger than a predetermined threshold value, pixels corresponding to the center portion of the light-emitting section cannot be distinguished from pixels corresponding to the peripheral portion of the light-emitting section, whereby the indication position of the indicator may not be accurately calculated. In particular, when the indicator including the image sensor moves at high speed, pixels corresponding to the light-emitting section may be spread in the moving direction of the indicator in the image acquired by the image sensor. If the indication position of the indicator is calculated based on these pixels, an accurate calculation result may not be obtained.